Food security has always been a top priority throughout the world, and an escalating concern for the environmental impact of crop production necessitates the development and use of novel methods to enhance productivity while protecting the environment Plant biologists develop and implement strategies for efficient production of crop plants with the aim of ensuring the availability of essential raw materials to the world's growing population. However, the development of biofuel and renewable technologies adds to this challenge since they have also become an increasingly important priority. Therefore, there is an increased need for improved approaches to enhance crop yield in diverse field conditions.
The multitude of different geographic environments and climates throughout the world present different types of challenges in generating increased biomass and yield potential in crop plants. Drought is a major factor which limits crop production globally. Long-term drought or short-term drought in the growing season can severely limit or even eliminate crop production. Changes in global weather patterns have affected the frequency and intensity of drought, even in prime cropping regions of the world.
Nutrient availability also limits crop production. Soil augmentation with nutrients is costly and energy intensive, and even when nutrients are available in sufficient quantities, crop plants are sometimes inefficient at nutrient uptake. Poor uptake of essential nutrients results in lower yields and food crops with lower nutritional values. For example, rice (the seed of the monocot plants Oryza sativa or Oryza glaberrima) is the most important staple food for over two-thirds the world's population, providing a significant proportion of the calories consumed. Since rice is the main staple food for much of the global population, producing rice with higher levels of iron can have a major impact on reducing micronutrient malnutrition throughout the world, as iron deficiency is one of the most widespread micronutrient deficiencies in humans worldwide.
Pathogen stress also limits productivity. Plants must invest energy to survive pathogen attack, and this diversion of energy results in lower yields. Plants also modify their composition to restrict disease progression, and these changes often make crop processing more difficult. Further, some crop pathogens cannot be limited effectively by genetic diversity, nor chemical control, and have significant impact on crop production globally.
Rice blast (Magnaporthe grisea or Magnaporthe oryzae) is a plant-pathogenic fungus that causes a serious disease affecting rice. It causes economically significant crop losses annually, contributing to an estimated 40% in crop yield. Rice blast destroys enough rice to feed millions of people throughout the world every growth season. Since rice is an important food staple for much of the world, the effects of rice blast have a broad impact on human health and the environment. Rice shortfalls contribute directly to human starvation. The rice blast further contributes to crop loss and requires the use of additional resources to compensate for reduced yield. There continues to be a great need for strategies that enhance various characteristics of plant growth in diverse growing conditions, such as tolerance to drought stress, tolerance to pathogen pressure, nutrient availability, and ultimately crop yield, so that greater amounts of food with increased nutrition can be available to the global population, and for other important benefits, such as biofuel production.